Surgical Pathology of Ascending Aortic Aneurysms: Are There Clinical Correlates of Elastic Fragmentation of the Tunica Media?
Stefania Rizzo, Marta Martin, Renato Razzolini, Gino Gerosa, Gaetano Thiene, Cristina Basso. University of Padua, Padua, Italy
Background: To evaluate: a) the prevalence of the different etiologies of ascending aorta aneurysms (AAA); b) the correlation between aortic diameters and elastic fragmentation score; c) whether aortic wall compliance depends on aneurysm size and elastic fragmentation score; d) whether aortic regurgitation presence and severity is related to the diameter of sinusal (AoS) or tubular portion (AoT) of aorta and if aortic valve replacement accounts for a hemodynamic benefit (reduction of end-diastolic volume EDV).
Design: Patients who underwent to ascending aorta replacement for AAA between 2001 and 2010, with or without aortic valve replacement, were included. Clinical, echocardiographic, surgical and histological data were retrospectively reviewed. At histology, we searched for: atherosclerotic, inflammatory and degenerative (elastic fragmentation and cystic medionecrosis) substrate. The latter was evaluated using the semiquantitative method by Larson and Edwards (score 1-4).
Results: 222 patients (mean age 60.9±13.1 yrs; 174 M, 78.4%) were enrolled, subdivided in 7 groups: arterial hypertension (n=95, 43.2%), bicuspid aortic valve (n=46, 20.7%), atherosclerosis (n=29, 13%), aortitis (n=10, 4.5%), previous aortotomy (n=8, 3.6%), Marfan syndrome (n=5, 2.25%), idiopathic aneurysms (n=29, 13%). The aortic valve was replaced in 144 patients (64.9%). The highest AoS diameter was observed in previous aortotomy (5.12 cm), while the highest AoT diameter in aortitis (5.65 cm). The AoS diameter positively correlated with the elastic fragmentation score (p<0.025), unlike the AoT diameter (p=0.336). Age directly correlated with the elastic fragmentation score (p<0.0001). The elastic fragmentation score was higher in patients with Marfan and aortitis (<0.001). Aortic compliance correlated with the elastic fragmentation score (p=0.017). In 135 patients with aortic regurgitation, the correlation between incompetence severity and AoS size was statistically significant (p=0.01). In patients with aortic valve replacement, the difference between median pre- and post-operative EDV is statistically significant (p<0.01).
Conclusions: The disease entity underlying AAA is variable, with hypertension being the most prevalent risk factor (43.2%). As age increases, the degree of elastic fragmentation also increases, regardless of the underlying etiology. The most severe degree of elastic fragmentation was observed in Marfan syndrome and aortitis. With increasing elastic fragmentation score, higher AoS and AoT diameters and lower aortic compliance are observed.
Wednesday, March 6, 2013 9:30 AM
Poster Session V # 57, Wednesday Morning